Recently, as the Visible Light Communication (VLC) technique, which enables wireless communication by adding communication functions to a visible light wavelength using an infrastructure in which lighting of incandescent bulbs or fluorescent tubes is replaced by Light Emitting Diode (LED) lighting, is actively studied and IEEE 802.15.7 international standard specification is completed, development of business models for commercialization is in progress. However, since IEEE 802.15.7 is generally limited to data transmission using a photo diode (PD), it has a problem in that a dedicated communication apparatus such as a VLC dongle or the like should be used. Accordingly, international standardization of Optical Wireless Communications (OWC), which mainly uses an image sensor such as a camera of a smart phone rather than a photo diode and includes infrared and ultraviolet wavelengths, as well as visible light, is progressed in IEEE 802.15.7r1 OWC TG (Task Group).
The inventor of the present invention is the chairman of IEEE 802.15.7r1 OWC TG of International Standard Organization, leading OWC international standardization by presenting many contributions related to OWC techniques, and the present invention relates to the Spatial 2-Phase Shift Keying (S2-PSK) modulation method, which is one of most essential techniques of OWC international standard techniques.